Thermostatic fuel control



ee. 22, i936; Q Wl HAHN 2,064,909

THERMOSTATIC FUEL CONTROL Filed July 25, 1932 for years.

Patented Dec. 22, 1936 PATENT OFFICE THERMOSTATIO FUEL CONTROL Otto W. Hahn, san Francisco, oaiif.

Application July 25;'1962, serial No. 624,505

13 Claims.

This invention relates to thermostatic control of fluid fuel supply to burners, particularly fuel gas supply, and has for its objects improved mechanism of this character which will operate directly upon the fuel valve mechanism With- Out the interposition of electric devices, also such mechanism which willbe absolutely fool-proof and will hold the main fuel Valve closed when no pilot flame is burning. Also a construction of the heat responsive element which will develop considerable movement and mechanical power inheating and cooling, and insure such operation Other Objects and advantages of the .v invention Willappear in the following description and accompanying drawing.

In the drawing Fig. l is a side elevation, partly in section, showing my improved thermostat-ic control apparatus on a gas burner.

Fig. 2 is a plan view of the left-hand portion of Fig. 1. l

Fig. 3 is an end view of the right-hand end of Fig. 1, partly in section, and -showing the gas valves closed.

Fig. 4 is a view similar to that of Fig. 3 butv showing the main burner gas valve and pilot gas feed open.

Fig. 5 is a fragmentary section of Fig. 4 as vseen from the line 5-5 thereof.

Fig. 6 is a side elevation showing a modification in the form of the heat responsive element.

In further detail the drawing shows a portion of a stove or fire box I of any desired heating equipment and within which is oneror more gas burners 2 taking the form of pipes with a row of holes 3 on top. These pipes 2 may join a transversely extending header or manifold 4 from which any-number of burner pipes may extend. The burner may take any other form than a straight pipe. Gas is `supplied to the header by a supply pipe 5 leading from a box 6 which may contain any desired thermostatic or other automatic control, not "shown, for raising, lowering, or extinguishing the iiame to suit the heating requirements and from which box the supply pipe 5' extends to a valve housing 1 forming part of the present invention, and which housing is made separable along the lines 8 and is provided with a vertical wall 9 forming an outer, I0, and an inner, II, Igas chamber ported through the wall by ports I2, I3,

closed or Opened simultaneously by a springactuated valve I4, and ports I5 and I6 -closedor opened simultaneously by a spring-actuated valve I1, the springs of the valves being shown respectively at I8 and I9 surrounding the respective valve rods which are fitted with heads 20, 2| for Opening thel valves by a rocking cam lever 22 pivoted at 23 to the valve housing, all as will be later explained. i

Port I2 leads from the receiving gas chamber (Cl. 15S-112.1)

I through chamber II to themain burner supply pipe and port I3 leads by way of a passageway 24 to a pilot flame gas supply pipe 25 at the outer end of which is a. vertically directed pilot ame burner 26 from the upper end of which a pilot ame 21 is adapted to burn.

Port I3 for supplying the pilot is under control of valve I4 and must open when the main burner port I2 Opens, but besides port I3 there is another port,` I5, kfor also supplying the pilot when valve I1 is open, as this port I5 also leads directly to passageway 24. Port I6 also controlled by valve I1 leads to a passageway 28 which supplies gas to a small horizontally extending pipe 29 which is openly slotted along its upper surface and leads to a ring-like burner 30 around the pilot so that when a flame burns from the ring 30 it will always be in a position to ignite the pilot when the pilot gas is turned on.

for thepilot gas will also be flowing in pipe 25 as v both ports I5 and I6 are simultaneously uncovered by valve I1.

Means is provided for manually opening valves I4 and I1 in the rocking lever 22, the pivot pin 23 of which is` secured to the lever to rock with it and which pin passes into the valve housing 1 through a packing hub 32 and carries a cam or block 33 which is fast on the pin and so shaped that upon right-#hand moving of lever 22 it will Contact head 20 of the stem of valve I 4 to open the valve against the spring (as shown in Fig. 4) and when rocked to the left it will permit this valve to close but will then open valve I1 (to the dotted position shown in Fig. 3), and when the handle stands vertical both valve's will be closed.

'Ihis rocking lever 22 is bifurcated at its lower end to form a pair of jaws or lugs, 34 and 35, lug 34 being herein termed the inner lug and lug 35 the outer lug. The lugs are spaced apart on the handle a. sufficient distance to pass the upper end 36' of a latch 36 which is mounted in such a way that it may be moved inwardly and Outwardly so as vto get into the path of either lug of the handle and thereby stop it from moving in that direction.

The latch 36 is a vertically arranged bar positioned freely in an open slot formed by extending walls 31 on the housing 1 and the lower end of the latch bar isvnotched or stepped as at 38 to rest upon and fulcrum against a fulcrum block 39 shown here as a U-shaped device (of good steel) positioned over a projection 40 of the valve housing Abetween the walls 31. This latch 6o bar is resiliently pushed outward at its upper end by a compression spring 4I recessed into both valve housing as well as the latch (see Fig. 1), and retained in place against the thrust of this spring by a horizontally extending rod 42 which passes freely through a hole 43 in the latch and through a round pin 44 seatedin a notch in the outer side of the latch bar and has an adjusting nut or nuts 45 at'its outer end. The opposite endr of the "rod'42 is'pivotally connected at 46 with the end of oneleg of an inverted U-shaped heat responsive element 4'| which arches over the pilot light flame ,and pivotally anchors at 48 at the end of its other leg to a supporting bar 49 which extends rigidly into the re box from the valve housing. The arrangement being such that as the horseshoe-shaped device 4l opens and closes it will pull or push a rod 42 to therebyeitherv pull A the latchv 36 inwardly or permit it to swing outwardly under influence of spring 4|.

. Latch 36 is, however, always free to be manually pushed inwardly'due' to the open notch in which pin 44 is seated, and to this end is provided with,a finger piece or push button 50.

It will be noted from Fig. l that in the position shown the latch fulcrums on the -upper corner of block 39 very close to the connectionof rod 42' so that a slight movement of rod 42 in an axial direction will result in -a relatively large movement of the upper or active end of. the latch, but in. moving outward the step portion 38 of the latch changesits fulcru'm` point from the upper corner of block 39 to the lower corner where a small tit 39' projects to-help hold the latch in proper positionand thus the fulcrum point being shifted further from rod 42 the movement of the latch becomes less with a given movement of the rod, but takes place under greater pressure.

The heat responsive member 4l' is of fiat chrome nickel steel' of horseshoe shape with heavy elongated arms, as shown, and has a curved row of round holes 5i through it :nearer to the inner arched line of the horseshoe so as to connect the inner, 4l', and outer,4l", curved portions with metal spokes and thereby reduce the heat conductivity between these two portions so that the pilot flame 21 in the position shown will maintain the inner arched portion 4l' at about a low redheat.v i

In the showing of Fig. 6 the pilot is shown at 52, its gas feed pipe 53, the slotted lighter tube 54, fixed supporting bar 55, latch-operating rod 56, all of the'same construction as described for Fig. l', but the heat responsive member here numbered 511s somewhat-'modified in form in having the vcircular row of holes 58 around one side of the largest or outer arch, and the pilot flame 53.

is arranged to give its maximum heat to the outer arch section. The upwardly extending end of the supporting bar 55 is slotted for free passage of a horizontally extending portion of the movable arm 51' of the horseshoe which connects l to the latch operating rod 56.

. mium and. 10% nickel, as this was found to combine a very high scaling point;l with great resist- 2,1.')64,90'9Y l i ance to corrosion, a high expansion coefficient,

and a practicallycomplete'and quickreversal cycle maintained through a period of years at a temperature of 1500 Fahrenheit.

It was found that with the horseshoeshape of heat responsive element chosen. a substantially,

uniform heat applied even up to a dull red heat'v had practically no effect on the latch control, for f f Asuch application of heat caused a uniform linear y l expansion of the elementl with substantially no outward or leverage movement of the arms, and hence if the pilot ame becomes accidentally extinguished the latch rod 42 will be at once retracted even with the full radiant heat from the 1.5

main burners or heated re box of a furnace in which it may be installed, playing freely upon the member, and this will result in the latch 36 i being withdrawn from the path of outer lg 35 of lever 22 so that it willpermit valve i4 to close .under energy of its spring I8 and thereby close both pilot port I3 and main burner port I2 and extinguish both llames. Continued retractionof the rod 42 will pull latch 36 to position in the path of inner lug` 34 so that lever 22 could not be swung to the right (as in Fig. 4) to open the main burner valve I4, but would be freed for swinging in the opposite direction (to the left as per dotted lines in Fig. l3) to thereby cause cam or block .33 to impinge valve stem head 2| and open valve i1 (to the dotted position in this figure). A'I'he handle 22 would, however, not stay in this position but would ily right back toneutral position (with bothvalves closed) unless held in open position for valve ll and a match touched to the slotted pipe at 3| .which willinstantly shoot a ame along this pipe to the ring burner t1 and thereby light the pilot also being supplied with gas by the opening of valve il, and the moment the pilot ignites the element di expands and releases latch 36 so that it is pushed out under force of spring 4| until it touches the inner face of outer lug 35 which then will overlie it as v indicated in Fig. 3, and since this will remove the I latch from the path of the inner lug 34 the lever will be freed to swing to the right for opening the main burner valve iB-as in Fig. 4. This means that the slotted igniter pipe feeder port i6 will be shut off as well as the pilot ame port i6, and

hence the slotted igniter pipe and ring burner llame will go out, but the pilot flame will not go out as the other pilot feeding port i3 is opened so quickly that the residual gas within the pilot Y flame pipe 25 will tide over this brief instant. As

' soon as lever 22 is swung to the right to open the main burner feed and pilot feed I3 latch 36 snaps outward in the path of lug 35 (as in Fig. 4) to lock the hand lever in this position.

If at any time it was desired 'to extinguish both the main burnerand pilot, button 5B may be pushed to force latch against spring 4| until the latch 'strikes the outer face of lug 34 (which lies just behind the latch as shown by thel dotted position of this lug in Fig. 4) and lies in the free u -I path between the two lugs so that the large valve yIii will snap closed. l

It will thusbe seen that the lever handle 22 can at rst only be moved to the left to permit light-v ing of the slotted igniter tube, that this ignites the pilot light, that the pilot light releases the lever handle'so that it may be swung in opposite direction, and that such a movement at once extinguishes the igniter tube, switches the gas feed of thev pilot'light and also turns on the main burner which is at' once ignited from the pilot.

' It will also be seen that at anytime the pilot goes out the main burner is shut oi and `cannot again be ignited without rstf lighting the pilot in the manner described. i

Having thus described my improved thermostatic fuel control apparatus'i't will be seen to be a class of mechanism wherein many'changes in details can be made without affecting the principles involved, and any such changes as come within the spirit of the invention are intended to be covered in my appended claims.

I claimz- 1. In a safety device for heaters the combination of a. heating member, a deformable element of one material having one edge adjacent to said heating member to receive the heat developed at said member, and having another edge more distant from the heating member to receive a lesser degree of heat developed at said member whereby said deformable element is deformed, .and means whereby said Ideformation of said deformable element allows the energizing of said heating member, and whereby its cooling and return to its normal shape cuts oi the means for energizing said heating member.

2. In a safety device for heaters the combination of a heating member and a deformable element having one edge adjacent to said heating member to readily receive the heat developed at said member, and having another edge more distant from the heating member to receive a'lesser degree of heat developed at said member, said dei formable element also having a series of perforations between its said hot and cooler edges to allow a relative movement between said hot and cooler edges by the stretching of a relatively small amount of material between said perforations', and to'also resist the passage of heat between said edges through the relatively small,

amount of material between said perforations.

3. In combination with a source of heat, a therlnos'tatic device comprising a at Vstrip of metal having one edge intermediate the ends of the strip disposed in closer heating proximity to said heat source than the opposite edge and having one end fixed whereby the opposite end'of the strip will flex in the plane of the strip.

4. In combination with a source of heat, a thermostatic device comprising a at strip of metal having one edge intermediate the ends of the strip disposed in closer heating proximity to said heat sourcethan the opposite edge and having one end fixed whereby thev opposite end of the strip will flex in the plane of the strip, said strip being arched edgewiseto form a substantially U- shaped member having a pair of legs an'd an intermediate connecting portion.

5. In combination with a source of heat, a thermostatic device comprising a flat strip of metal having one edge intermediate the ends of the stripdisposed in closer heating proximity to said heat source than the opposite edge and having one end fixed whereby the opposite end of the strip will iiex in the plane of the strip, said strip having at least one opening between the heated edge portion and the opposite edge portion.

6. In combination with a source of heat a ther- Y.

'Y mostatic device comprising a fiat strip of metal being arched edgewise to form .a substantially U-shaped member having a pair of legs and an intermediate connecting portion, said-strip having at least one opening between the heated edge portion and the opposite edge portion.

7. The device of claim-6 characterized by having the opening in the connecting portion, and the source of heat located adjacent said connect ing portion and between the legs.

8. A thermostatic device comprising a substantially 'iiat elongated plate of metal formed substantially to U-shape -in the plane of the plate and arranged for anchoring at one end to a support and withthe opposite end of the plate free to move, and whereby when said anchored plate is heated at one edge adjacent the U-bend the free end will move in the plane of the plate for doing useful work, the cross sectional area of the metal in said plate being reduced along the inner or concave portion of the U-bend whereby said portion will expand more readily than the outer portion of the bend upon application of heat.

9. A thermostatic device comprising asubstantially flat elongated plate of metal formed substantially to U-shape in the plane of the plate and arranged for anchoring at one end to a support and with the Opposite end of the plate free tc move, and whereby when said'anchored plate is heated at one edge adjacent the U-bend the free end will move in the plane of the plate for doing useful work, the cross sectional area of the-metal in said plate being reduced along the inner or concave portion of the U-bend by holes formed therethrough whereby said portion will expand more readily than the outer portion of the bend upon application of heat.

10. A -thermostatic element vcomprising an elongated plate of corrosion-resisting metal formed into substantially U-shape in the plane of the plate, and the section of the metal weakened along the margin of the curve of the U so that when heat is applied to the weakened area the ends of the plate will move relatively to one another in the plane of the plate for doing useful work.

11. A thermostatic element comprising an elongated plate of corrosion-resisting metal formed into substantially U-shape inthe plane of the plate, and the section of themetal weakened by an opening in the plate along the margin of the U so that when heat is applied to the weakened area the ends of the plate will move relatively to one anotherv in the plane of the plate for doing useful work.

12. A thermostatic element comprising an elongated plate of corrosion-resisting metal formed into substantially U-shape in the plane of the plate, and the section of the metal weakened by a plurality of openings in the plate along the margin of the U so that when heat is applied to the weakened area the'ends of the plate will move relatively to one another in the plane of the plate for doing useful work.

13. A thermostatic element comprising an elongated plate of corrosion-resisting metal weakened along one margin at a point intermediate the ends of the plate, so that when heat is applied'to the weakened area the ends of the plate will move relatively to one another in the plane of the plate for doing useful work.

O'I'I'O W. HAHN. 

